X0306 4 2022-03-15 0 0000315293 Aon plc AON 0001782945 Zeidel Darren 200 EAST RANDOLPH ST. CHICAGO IL 60601 0 1 0 0 General Counsel Class A Ordinary Stock 2022-03-15 4 M 0 148 A 15277 D Class A Ordinary Stock 2022-03-15 4 F 0 66 307.62 D 15211 D Class A Ordinary Stock 2022-03-16 4 S 0 82 308.31 D 15129 D Restrictive Share Unit (Right to Receive) 2022-03-15 4 M 0 148 0.00 D 2022-03-15 Class A Ordinary Shares 148 0 D Class A Ordinary Shares acquired upon the vesting of a restricted share unit award. Class A Ordinary Shares withheld by the issuer for payment of withholding taxes in connection with the vesting of the award. The transactions reported were effected pursuant to a trading plan meeting the requirements of SEC Rule 10b5-1 entered into on November 23, 2021. The restricted share unit award converts to Class A Ordinary Shares on a 1-for-1 basis. In accordance with Irish law, the reporting person agreed to pay the issuer the nominal value of US$0.01 per share issued to the reporting person. A restricted share unit award was granted on March 15, 2019 and vests in accordance with the terms of the Aon plc 2011 Incentive Compensation Plan: 33 1/3% of the award vests on each of the first through third anniversary of the date of grant. /s/ Julie Cho - Julie Cho pursuant to a power of attorney from Darren Zeidel 2022-03-17